Male electric plug



May 8, 1956 w. H. COOK 2,745,077

MALE ELECTRIC PLUG Filed Aug. 30, 1954 IN V EN TOR.

United States Patent() ice MALE ELECTRIC PLUG William H. Cook, Toledo, Ohio Application August 30, 1954, Serial No. 452,774

1 Claim. (Cl. 339-99) This invention relates to male electrical plugs.

It is an object of the present invention to provide a male electrical plug which permits the operative connection therewith of the usual electrical cord merely by inserting the cord into the plug and then pulling the same outwardly, eliminating the need for screw drivers, levers and the like, and making the connection entirely automatic.

It is another object of the present invention to provide a male electrical plug which is foolproof, durable, that makes contact by merely inserting and then pulling on the elecrtical cord or wire and permits the changing of wire in a matter of seconds.

It is still another object of the present invention to provide a male electrical plug where in the wire cannot be removed from the plug nor contact broken while the plug remains inserted within the socket, and which cannot short itself.

Other objects of the present invention are to provide a male electrical plug having the above objects in mind which is of simple construction, has a minimum number of parts, inexpensive to manufacture, is easy to use and efiicient in operation.

For other objects and a better understanding of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawing, in which:

Figure 1 is a perspective view of a male electrical plug and embodying the features of the present invention;

Fig. 2 is a front elevational view thereof with the cover plate removed and showing the electrical cord after it has been inserted into the plug just prior to being pulled outwardly into engagement therewith;

Fig. 3 is a view similar to Fig. 2 but showing the electrical cord in section and after the same has been pulled outwardly into engagement with the plug and Fig. 4 is a transverse sectional view taken along the line 4-4 of Fig. 2 and showing the prongs in contact with the conductor wires.

Referring now more in detail to the drawing, rep resents a mounting block of plastic or other suitable material to which a cover plate 11 is secured by means of the through screws 12, substantially as illustrated.

As shown in Figs. 2 and 3 the inner face of the block 10 is provided with a central longitudinal groove or passage 13 extending from end to end and within which is received the electrical cord made up of the pair of conductor Wires 14 and the rubber coating 15. The end of the groove 13 is enlarged, as at 16 to facilitate the insertion therewithin of the electrical cord. The inner face of the block 10 on opposite sides of the channel 13 is provided with a pair of complementary recesses 17 and 18, the recess 17 being of less depth than the recess 18. The recesses 17 and 18 are each integrally formed with the bosses 19 and 20, respectively, on which are rotatably mounted the brass pawls 21 and 22. As shown in Fig. 2, the pawls 21 and 22 are adapted to move to an inopera- 2,745,077 Patented May 8, 1956 tive position out of the path of the electrical cord to permit the ready and easy insertion of the latter, being limited in this position by the integrally formed stops 23 and 24. v

The inner face of the block 10 is provided on opposite sides of the channel 13 with a pair of complementary r tive material.

i The tapered disposition of the grooves 26 permits the rotation of the pawls 21 and 22 to the inoperative posi tion of Fig. 2, upon the insertion of the electrical cord, which movement causes the inner ends of the prongs 27 to be displaced outwardly against their own resilience. Thus, a slight pressure is inserted against the electrical cord as it is inserted by the pawls 21 and 22. By providing the recesses 17 and 18 of varying depth (Fig. 4), it will be noted that the pawls 21 and 22 will each engage one of the halves of the electrical cord in alignment with their interior conductors 14.

The inner face (Fig. 4) of the cover plate 11 is integrally formed with the projections 31 and 32 of varying thickness and which are adapted to fit snugly within the recesses 17 and 18, respectively whereby to retain the pawls 21 and 22 on their bosses 19 and 20 as well as to prevent longitudinal displacement of the cover 11 relative to the block 10. The block 10 at the end of the channel 13 adjacent the prongs 27 is also provided with the recesses 33 and 34 (Fig. 2) which receive therewithin correspondingly shaped protrusions integrally formed on the inner face of the cover 11, not shown.

In operation, the electrical cord 14, 15 is inserted into the channel 13 through the enlargement 16, the pawls 21, 22 being moved to an inoperative position (Fig. 2) against the resilience of prongs 27 and permitting the passage of the cord. Upon the cord then being pulled outwardly in the opposite direction, the points of the pawls will consecutively engage the coating 15 until in their operative position (Figs. 3 and 4) they will penetrate into the conductor 14 to establish electrical contact therewith, it being noted that the cam surfaces 30 of the pawls 21, 22 are at all times in resilient contact with the inner ends of the prongs 27. It will be noted that each successive point on the pawls 21, 22 is longer than the preceding one (further from the fulcrum point, thus effecting a deeper penetration the harder the wire is pulled until the pawl has been rotated its maximum distance away from the position of Fig. 2, where they are stopped by the guards 35 and 36, integrally formed in block 10). Thus the harder the cord is pulled, the firmer the contact with the conductors 14 by the pawls 21, 22. Should the wire leading from the plug become damaged or a longer wire desired, the wire connected to the plug can be severed near the point of entrance. The portion of the wire thus remaining engaged in the pawl is then pushed outwardly between the prongs 27, where it will drop off and a new wire inserted. Upon pulling the latter, positive contact is immediately established with the terminals 27 through the prongs 21, 22.

It will be readily apparent to those skilled in the art that the principle of the invention is not limited to male plugs but may be applied to other electrical terminals, fixtures and sockets and that the materials employed in the construction of the plug are not limited to plastic and brass but include similar suitable other materials.

Furthermore, the entrance path of the electrical cord need not be limited to the particular form shown in the drawings.

Preferably the plastic block 10 and cover 11 will be colored red and treated with suitable powders or chemicals so as to impart phosphorescence to the plug.

While various changes may be made in the detail construction, it shall be understood that such changes shall be within the spirit and scope of the present invention as defined by the appended claim.

What I claim as new and desire to protect by Letters Patent of the United States is:

A male plug comprising positioning means, a pair of conductor prongs mounted in said positioning means, corresponding ends of said prongs extending outwardly of said positioning means and being adapted to be inserted into a female outlet, the inner ends of said prongs extending within said positioning means and being oppositely disposed therewithin, said positioning means having a central longitudinal bore extending therethrough intermediate said prongs and adapted to receive therewithin an electrical cord, oppositely disposed pawls of conductive material rotatably mounted within said positioning means on opposite sides of said bore, said pawls being displaced laterally with respect to each other whereby to engage opposite sides of the electrical cord, said positioning means being adapted to permit the lateral flexing of the inner ends of said prongs, each of said pawls having a cam surface in contact with the inner end of the adjacent prong, said pawls being adapted to permit the inward movement of the electrical cord and to pierce said cord upon the latter being pulled outwardly so as to establish contact with the conductor wires therewithin,

References Cited in the file of this patent UNITED STATES PATENTS 1,526,265 Bergman Feb. 10, 1925 1,825,638 Schutt Sept. 29, 1931 1,960,191 Staub May 22, 1934 2,482,214 Rogie Sept. 20, 1949 2,609,415 Benander Sept. 2, 1952 FOREIGN PATENTS 993,178 France July 18, 1951 

